Contribution of cryptogamic covers to the global cycles of carbon and nitrogen
Contribution of cryptogamic covers to the global cycles of carbon and nitrogen
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DOI：
10.1038/ngeo1486
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发表时间：
2012-07-01
影响因子：
18.3
通讯作者：
Poeschl, Ulrich
中科院分区：
文献类型：
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作者：
Elbert, Wolfgang;Weber, Bettina;Poeschl, Ulrich
许多陆地表面，包括土壤，岩石和植物，都被光合自养群落所覆盖，能够利用阳光作为能源，从无机物质中合成自己的食物（1，2）。这些群落被称为隐花植物覆盖物，由不同比例的蓝藻、藻类、真菌、地衣和苔藓组成，能够固定大气中的二氧化碳和氮（3）。然而，它们对全球和区域碳和氮的地球化学循环的影响尚未得到评估。在这里，我们分析了以前发表的数据上的空间覆盖的隐花植物群落，以及相关的碳和氮通量，在不同类型的生态系统在地球仪。我们估计，在全球范围内，隐花植物覆盖每年吸收约3.9 Pg碳，相当于陆地植被净初级生产量的7%左右。我们推导出隐花植物覆盖每年约49 Tg的氮吸收，这表明隐花植物覆盖占陆地生物固氮的近一半。我们认为，隐花植物覆盖固氮可能是至关重要的植物固碳。
Many terrestrial surfaces, including soils, rocks and plants, are covered by photoautotrophic communities, capable of synthesizing their own food from inorganic substances using sunlight as an energy source(1,2). These communities, known as cryptogamic covers, comprise variable proportions of cyanobacteria, algae, fungi, lichens and bryophytes, and are able to fix carbon dioxide and nitrogen from the atmosphere(3). However, their influence on global and regional biogeochemical cycling of carbon and nitrogen has not yet been assessed. Here, we analyse previously published data on the spatial coverage of cryptogamic communities, and the associated fluxes of carbon and nitrogen, in different types of ecosystem across the globe. We estimate that globally, cryptogamic covers take up around 3.9 Pg carbon per year, corresponding to around 7% of net primary production by terrestrial vegetation. We derive a nitrogen uptake by cryptogamic covers of around 49 Tg per year, suggesting that cryptogamic covers account for nearly half of the biological nitrogen fixation on land. We suggest that nitrogen fixation by cryptogamic covers may be crucial for carbon sequestration by plants.